I have a 2010 e60 with N52k.

I'm buying a new head unit to go from 8 inch display to 16 inch display.

I have watched a ton of Youtube videos on how to remove the dashboard and install the new head unit display.

None of the videos recommended removing the negative side of the battery before starting the process.

Is there any live power going to the:

- display unit ?
- iDrive controller ?
- CD player ?
- CCC unit ?

I know you have to remove the hazard switch and door open switch near the air vents in the process of installing a new display screen...and that does have continuous power.

Why wouldn't these installers be disconnecting the battery first?

 

There is nothing at the CID, IHKA, or M-ASK/CCC that is inherently sensitive enough to require disconnecting the negative terminal. That said, best practice is always to disconnect the battery regardless. While it's extremely difficult to damage KL15 or KL30 under normal conditions, issues typically arise when someone starts splicing wires and accidentally shorts a circuit.

If you are not cutting or splicing any wiring, you are generally fine. However, the moment splicing is involved, the negative terminal should be disconnected as a precaution. I'll emphasize this again: if you do not fully understand what you're working on, disconnect the battery, no exceptions.

I've completed retrofits without disconnecting the battery, but that's only because I understand the BMW power management system and know exactly what I'm touching. Even then, if splicing is required, I always disconnect the negative terminal for peace of mind.

 

I'll do some risk management and proactively pull the negative wire on the battery.

Next...

When I read the reviews for all the "after market" android display screens that are 14 inch or 16 inch I'm surprised that so many people are dissatisfied with the manufacturer or functionality of these large displays.

Just when I studied xTron's displays and it appeared they are a quality player in this space, I read a bunch of reviews about how terrible the xTron screens were.

Is there one after market display manufacturer that is likely better than the rest or are they all made at the same factory in China?

 

I think you're going to find most of these things are of poor quality. I once had the Avin 8.8" unit and it was okay build quality, but the software reliability on it was lacking. It's one of the big reasons I went with a Mr12Volt system so that I can retain the original screen and just add CarPlay to it.